Helmet with padding arrangement

ABSTRACT

A helmet having an outer shell defining a convex outer surface and an opposite concave inner surface circumscribing an inner cavity to receive the wearer&#39;s head is provided. The helmet has an inner liner connected to the outer shell and located in the inner cavity, where the inner liner contacts the wearer&#39;s head when the helmet is worn. The inner liner includes a padding arrangement including a plurality of padding substructures disposed at selected locations in the inner cavity, where at least one of the plurality of paddings has a shear resistance along a shear direction lower than a compressive resistance along a compressive direction, where the compressive direction extends transversally to the shear direction. The helmet also has an attachment device for securing it on the wearer&#39;s head.

TECHNICAL FIELD

The present disclosure relates generally to protective equipment, and more particularly to padding arrangements and protective helmets with such padding arrangements.

BACKGROUND OF THE ART

Concussions and other traumatic injuries while practicing sports or doing other activities is a major concern for protective equipment manufacturers and has gained the attention of the public. Impact protection technologies such as in the helmet industry or for other protective equipment in sports (e.g. football, hockey, bicycling, motorsports, and other sports), and other activities involving injury risks from single or multiple impacts to the head have been contemplated to reduce the amount of impact energy transmitted to the head/brain. In other words, energy absorption features for helmets and other protective devices have been a design consideration of protective equipment manufacturers to prevent or reduce the risks for concussions and/or traumatic injuries due to single or multiple impacts on the head.

Despite countless attempts to implement technologies for reducing the risks for concussion and/or traumatic injuries, reducing linear and/or angular acceleration to the head/brain caused by impact energy transmission and/or improving impact energy absorption of padding arrangements and/or helmets having such padding arrangements, there is still a need for improvements to more efficiently reduce impact energy transmitted to the head, such as impact energy resulting from linear acceleration, rotational acceleration, and/or a combination of linear and rotational acceleration.

SUMMARY

Therefore, it is an aim of the present disclosure to provide padding arrangements and helmets having such padding arrangements that address issues associated with the prior art.

In accordance with one aspect of the present disclosure, there is provided a helmet for wearing on a wearer's head, the helmet comprising: an outer shell defining a convex outer surface and an opposite concave inner surface circumscribing an inner cavity to receive the wearer's head; an inner liner connected to the outer shell and located in the inner cavity, the inner liner contacting the wearer's head when the helmet is worn, the inner liner including a padding arrangement including: a plurality of padding substructures disposed at selected locations in the inner cavity, at least one of the padding substructures having a shear resistance along a first shear direction lower than a shear resistance along a second shearing direction, the second shear direction extending transversely to the first shear direction, and the first and second shear directions extending transversely to a thickness of the at least one of the padding substructures; and an attachment device for securing the helmet on the wearer's head.

Further in accordance with the aspect, for instance, the at least one of the padding substructures includes a plurality of separate substructure segments.

Further in accordance with the aspect, for instance, the separate substructure segments are interconnected to one another.

Further in accordance with the aspect, for instance, the at least one of the padding substructures includes a frontal substructure located in a foremost portion of the helmet within the inner cavity, the frontal substructure extending in a front-to-back direction of the helmet from adjacent to a front peripheral edge of the helmet towards a top of the helmet, the frontal substructure configured to face a frontal zone of the wearer's head such as to cover at least part of a forehead of the wearer's head.

Further in accordance with the aspect, for instance, the first shear direction of the frontal substructure extends in a front-to-back direction, from a front peripheral edge of the outer shell, along a sagittal plane of the helmet.

Further in accordance with the aspect, for instance, the at least one of the padding substructures includes an elevated lateral substructure located in a lateral portion of the helmet within the inner cavity to face a side of the wearer's head.

Further in accordance with the aspect, for instance, the first shear direction of the elevated lateral substructure extends upwardly towards a top of the helmet.

Further in accordance with the aspect, for instance, the at least one of the padding substructures includes a posterior lateral substructure located in a lateral portion of the helmet within the inner cavity to face a side of the wearer's head within the inner cavity that is closer to an occipital portion of the helmet than a frontal portion of the helmet.

Further in accordance with the aspect, for instance, the first shear direction of the posterior lateral substructure extends rearwardly with respect to the helmet, towards an occipital portion of the helmet.

Further in accordance with the aspect, for instance, the at least one of the padding substructures includes an occipital substructure located in an occipital portion of the helmet within the inner cavity, the occipital substructure is configured to face an occipital zone of the wearer's head.

Further in accordance with the aspect, for instance, the first shear direction of the occipital substructure extends in a back-to-front direction, from a rear peripheral edge of the helmet and along a sagittal plane of the helmet.

In accordance with another aspect, there is provided a helmet for wearing on a wearer's head, the helmet comprising: an outer shell defining a convex outer surface and an opposite concave inner surface circumscribing an inner cavity to receive the wearer's head; an inner liner connected to the outer shell and located in the inner cavity, the inner liner contacting the wearer's head when the helmet is worn, the inner liner including a padding arrangement including: a plurality of padding substructures disposed at selected locations in the inner cavity, at least one of the padding substructures having a shear resistance along a shear direction lower than a compressive resistance along a compressive direction, the compressive direction extending transversally to the shear direction; and an attachment device for securing the helmet on the wearer's head.

Further in accordance with the aspect, for instance, the at least one of the padding substructures includes a plurality of separate substructure segments.

Further in accordance with the aspect, for instance, the separate substructure segments are interconnected to one another.

Further in accordance with the aspect, for instance, the at least one of the padding substructures includes a frontal substructure located in a foremost portion of the helmet within the inner cavity, the frontal substructure extends in a front-to-back direction of the helmet from adjacent to a front peripheral edge of the helmet towards a top of the helmet, the frontal substructure is configured to face a frontal zone of the wearer's head such as to cover at least part of a forehead of the wearer's head.

Further in accordance with the aspect, for instance, the shear direction extends in a front-to-back direction, from a front peripheral edge of the outer shell, along a sagittal plane of the helmet.

Further in accordance with the aspect, for instance, the at least one of the padding substructures includes an elevated lateral substructure located in a lateral portion of the helmet within the inner cavity to face a side of the wearer's head.

Further in accordance with the aspect, for instance, the shear direction extends upwardly towards a top of the helmet.

Further in accordance with the aspect, for instance, the at least one of the padding substructures includes a posterior lateral substructure located in a lateral portion of the helmet within the inner cavity to face a side of the wearer's head within the inner cavity that is closer to an occipital portion of the helmet than a frontal portion of the helmet.

Further in accordance with the aspect, for instance, the shear direction extends rearwardly with respect to the helmet, towards an occipital portion of the helmet.

Further in accordance with the aspect, for instance, the at least one of the padding substructures includes an occipital substructure located in an occipital portion of the helmet within the inner cavity, the occipital substructure is configured to face an occipital zone of the wearer's head.

Further in accordance with the aspect, for instance, the first direction extends in a back-to-front direction, from a rear peripheral edge of the helmet and along a sagittal plane of the helmet.

DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of a helmet with a padding arrangement in accordance with embodiments of the present disclosure;

FIG. 1A is a frontal view of a human skull showing a zone of a wearer's head corresponding to portions of the padding arrangement of the helmet of FIG. 1;

FIG. 1B is a side elevational view of the human skull shown in FIG. 1A, showing zones of a wearer's head corresponding to portions of the padding arrangement of the helmet of FIG. 1;

FIG. 1C is a posterior view of the human skull shown in FIG. 1A, showing zones of a wearer's head corresponding to a portion of the padding arrangement of the helmet of FIG. 1;

FIG. 1D is another side elevational view of the human skull shown in FIG. 1A, showing another zone of a wearer's head corresponding to a portion of the padding arrangement of the helmet of FIG. 1;

FIG. 1E is another side elevational view of the human skull shown in FIG. 1A, showing another zone of a wearer's head corresponding to a portion of the padding arrangement of the helmet of FIG. 1;

FIGS. 1F to 1N are other side elevational views of the human skull shown in FIG. 1A, showing other zones of a wearer's head corresponding to other contemplated portions of padding arrangement;

FIG. 2 is a front perspective view, partly cutaway, of a portion of the padding arrangement of the helmet shown in FIG. 1, according to an embodiment;

FIG. 3 is a rear perspective view, partly cutaway, of the portion of padding arrangement shown in FIG. 2;

FIG. 4 is a cross-sectional lateral view of the helmet of FIG. 1;

FIG. 5 is a bottom perspective view of a helmet with a padding arrangement, in accordance with another embodiment of the present disclosure;

FIG. 6 is another perspective view of the helmet shown in FIG. 5;

FIG. 7 is a rear elevational view of the helmet shown in FIGS. 5-6;

FIG. 8 is a left side elevational view of the helmet shown in FIGS. 5-7;

FIG. 9 is a cross-sectional view taken along the sagittal plane S-S of the helmet shown in FIGS. 5-8;

FIGS. 10A, 10B, 10C, 10D and 10E are schematic representations of contemplated deformation directions of adjacent padding substructures of the padding arrangement of the helmet of FIGS. 1-9 according to various embodiments.

FIGS. 11-12 are cross-sectional lateral views of examples of padding substructure of the padding arrangement of FIG. 1, according to some embodiments;

FIGS. 13A-13B are cross-sectional lateral views of examples of padding substructure of the padding arrangement of FIG. 1, according to some other embodiments;

FIG. 14 is a cross-sectional lateral view of a padding substructure of the padding arrangement of FIG. 1, according to an embodiment;

FIGS. 15-16 are cross-sectional lateral views of variants of the padding substructure shown in FIG. 14; and

FIG. 17-21 are cross-sectional lateral views of other variants of the padding substructure as shown in FIG. 14;

FIGS. 22-23 show exemplary cross-sections of channels of the padding substructures, according to some embodiments.

DETAILED DESCRIPTION

Referring to the drawings, and more particularly to FIG. 1, there is illustrated a helmet 1 in accordance with the present disclosure. The helmet 1 has an outer shell 10 and an inner liner 20 including a padding arrangement 30 adapted to reduce the impact energy transmitted to the head and/or brain of a user wearing the helmet 1 upon receiving an impact on the helmet 1. The helmet 1 may optionally have an attachment device 40 to secure the helmet 1 on the wearer's head. Different embodiments of the outer shell 10, the inner liner 20, the padding arrangement 30, components forming such padding arrangement 30 and how the inner liner 20 may reduce the impact energy transmitted to the head and/or brain are discussed later below.

The helmet 1 of FIG. 1 is a generic helmet. However, in some embodiments, such helmet 1 and inner liner 20, including the padding arrangement 30, may be suitable for other sports, where single or frequent impacts to the head may happen while practicing the sport. For instance, the helmet 1 may be a football helmet, a hockey helmet, a bicycle helmet (a.k.a., a cycling helmet), a motorsports helmet (e.g. car racing helmet, motorcycle helmet), a climbing helmet, a snow sport helmet, or helmets for other sports. The helmet 1 may also be a safety helmet, such as used by workers on construction sites, for instance. That is, the helmet 1 and inner liner 20 may be adapted for other specific types of activities involving risks of single or multiple impacts to the head without departing from the present disclosure.

The attachment device 40 is typically anchored to the outer shell 10 of the helmet 1, though the attachment device 40 may optionally be attached to other components of the helmet 1 in addition to or instead of the outer shell 10. For instance, the attachment device 40 may be attached to the inner liner 20. The attachment device 40 comprises attachment components, such as straps (e.g. soft straps such as straps made of fabric or nylon mesh, and/or rigid straps, such as made of plastic material)) or other features to secure the helmet 1 on the wearer's head. The attachment device 40 may be adjusted to allow for a customized fit of the helmet 1 on the wearer's head and ensure the helmet 1 is secured to the wearer's head. In some cases, the attachment device 40 may include a chin strap (not shown) as typically found on hockey or lacrosse helmets, bicycle helmets, or the like. The attachment device 40 may additionally or alternatively include other attachment components adjustable to properly maintain the helmet 1 on the wearer's head when performing the activity for which the helmet 1 is intended. Additional components may be connected to the outside of the helmet 1. For instance, the helmet may also include attachment means for securing (permanently or removably securing) a visor, a cage, a facemask or face protection devices and/or other components to the helmet 1, such as portable cameras or other electronic devices, depending on the types of activity the helmet 1 is intended for. In some embodiments, the helmet 1 may include an adjustment mechanism for customizing the fit of the helmet 1 and/or the padding arrangement 30 according to the wearer's preferences. In such cases, the adjustment mechanism may be accessible from the inside or outside of the helmet 1.

The helmet 1 is defined by an occipital portion, a frontal portion, opposite lateral portions and a top portion. Each of these portions covers a corresponding region of the wearer's head when the helmet 1 is worn. That is, the occipital portion of the helmet 1 is configured to cover an occipital region of the head, above the wearer's neck, the opposite lateral portions of the helmet 1 are configured to cover opposite lateral regions (temporal or side regions) of the wearer's head, the frontal portion of the helmet 1 is configured to cover a frontal region of the wearer's head, and the top portion of the helmet 1 is configured to cover a top portion of the wearer's head. These different portions of the helmet 1 may correspond to or be divided into zones of the wearer's head to be protected against impact. Such zones on the wearer's head may be transposed (or “reflected” into) to respective portions of the inner liner 20 and the padding arrangement 30. As will be discussed later, these different portions of the helmet 1, more specifically the respective portions of the inner liner 20 and the padding arrangement 30 include zone-specific sets of features for customizing their respective behaviour when experiencing a rear impact, a lateral impact, a frontal impact and/or a top impact, for example, depending on their respective locations within the inner cavity of the helmet 1.

To illustrate an example of the zones of the wearer's head that face and/or correspond to respective portions of the inner liner 20 and padding arrangement 30 discussed later, a human skull SK is shown with views taken in different orientations in FIGS. 1A to 1E. As shown in these figures, the darkened zones correspond to respective zones of the wearer's head that face and/or correspond to respective portions of the inner liner 20 and padding arrangement 30. The direction of the arrows on these figures will be described later with more details. The arrows correspond to an example of contemplated preferential deformation directions characterizing the padding arrangement 30, where such directions may correspond to the most frequent and/or critical/damaging load (impact load) conditions applied on the wearer's head and the helmet 1 according to given sports or situations in use.

As shown on FIGS. 1A and 1B, a frontal zone FZ is defined as a zone extending from above the orbit O toward the pole of the skull SK. The frontal zone FZ covers a substantial portion (e.g., more than 50%) of the frontal bone FB, up to all of the frontal bone FB. When viewed in the side elevational view (see FIG. 1B), the frontal zone FZ extends from a forwardmost point of the skull SK above the orbits O towards the back of the skull. The frontal zone FZ may cover at least part of the lateral extensions of the frontal bone FB above the temporal bone TB on opposed sides of the skull SK. The frontal zone FZ ends forward of the ears, or forward of the temporomandibular articulation TA.

As shown in FIGS. 1B and 1C, an occipital zone OZ is defined as a zone extending from a lower section of the occipital bone OB toward the pole of the skull SK. The occipital zone OZ may define a substantial portion of the rear portion of the skull SK, or stated differently a substantial portion of a projected cross-section area in a plane facing the rear of the skull SK (posterior view, such as in FIG. 1C). The occipital zone OZ covers at least part of the occipital bone OB and part of the parietal bone PB. The occipital zone OZ extends in a back-to-front direction of the skull SK along a sagittal plane of the skull SK, and extends transversally to the posterior-to-anterior direction towards the temporal bones TB on opposite sides of the skull SK. The occipital zone OZ may end rearward of the ears, or temporal bones TB, when viewed in a side elevational plane (see. FIG. 1B). The occipital zone OZ may cover up to all of the posterior zone of the skull SK up to the junction between the squamous suture SS1 and the lambdoid suture SS2.

As shown in FIG. 1D, an elevated lateral zone ELZ is defined as extending upwardly from the ear toward the sagittal suture SS3, or from the external auditory canal AC to the sagittal suture SS3. The elevated lateral zone ELZ covers part of the parietal bone PB and the temporal bone TB. As shown, the elevated lateral zone ELZ may cover part of the lateral extensions of the frontal bone FB, which is adjacent the coronal suture SS4 when viewed in FIG. 1D.

As shown in FIG. 1E, a posterior lateral zone PLZ is defined as extending laterally rearward of the helmet 1, between the external auditory canal AC and the sagittal suture SS3. The posterior lateral zone PLZ may cover part of the temporal bone TB and of the occipital bone OB. The posterior lateral zone PLZ covers up to all of the lateral portion of the skull SK from behind the ear (or from rearward of the external auditory canal AC).

At junction areas between adjacent ones of the frontal zone FZ, the occipital zone OZ, the elevated lateral zone ELZ, and the posterior lateral zone PLZ, transition or overlapping zones may be defined between adjacent zones. Referring to FIGS. 1F to 1N, transition zones TZ, which may also be referred to as overlapping zones, may be defined at a junction between adjacent ones of the frontal zone FZ, occipital zone OZ elevated lateral zone ELZ, and the posterior lateral zone PLZ. The transition zones TZ may spread over a surface area of adjacent ones of the frontal zone FZ, occipital zone OZ elevated lateral zone ELZ, and the posterior lateral zone PLZ. Such transition zones TZ may be transposed to selected areas of the inner liner 20 and/or padding arrangement 30. This will be discussed later with respect to embodiments of the inner liner 20 and padding arrangement 30.

Returning to FIG. 1, the outer shell 10 defines an outer surface of the helmet 1. The outer shell 10 has an hemispherical shape. The outer shell 10 thus defines a convex outer surface (exposed outer surface of the helmet 1). The outer shell 10 defines an inner cavity 11 of the helmet configured to receive the inner liner 20 and portions of the wearer's head when the helmet 1 is worn. The outer shell 10 may have vent holes defined therethrough to channel outside air into the helmet 1 for comfort of the wearer and cooling the inner cavity 11 of the helmet 1 during use. Although the outer surface of the helmet 1 is relatively smooth to increase the likelihood to slide on surfaces or against projectiles that may impact the helmet 1, the outer shell 10 may have various shapes, geometries and/or surface finish for aesthetic purposes or with some practical functions. For instance, the outer shell 10 may define a combination of curved and/or profiled surfaces for enhancing aerodynamic properties of the helmet 1. Additionally or alternatively, the outer shell 10 may provide access to and/or include the adjustment mechanism of the helmet 1, in embodiments where such adjustment mechanism(s) is/are present. For instance, one or more actuator(s) of the adjustment mechanism(s) of the helmet 1 may be disposed on the outer shell 10, and accessible from the outside of the helmet 1, such that a wearer may operate the adjustment mechanism, manually or using a tool, while wearing the helmet 1.

In some embodiments, the helmet 1 may be adjustable, such that the size and/or shape of the helmet 1 may be adjusted longitudinally and/or laterally by the wearer to allow for a customized fit of the helmet 1 on the wearer's head. This is often viewed in the hockey helmets and ski helmets industry, for instance. As such, in some embodiments, the outer shell 10 may include a plurality of shell portions that are movable relative to one another to adjust a size and/or shape of the helmet 1. For instance, a first and a second portion of the outer shell 10 may be slidably connected to one another and/or pivotally connected to one another to vary dimensions of the inner cavity 11 of the helmet 1. In such cases, the inner liner 20, including the padding arrangement 30, is configured to adapt to the movement of the shell portions relative to one another. That is, the inner liner 20 may be connected to one or more of the shell portions such as to allow the shell portions and/or components forming the padding arrangement 30 to move relative to one another. In some embodiments, the helmet 1 is made of a single outer shell 10, such as shown in FIG. 1.

The outer shell 10 is typically rigid and relatively thin when compared to the inner liner 20 of the helmet 1. Hence the outer shell 10 may be referred to as a hard shell. The outer shell 10 is made of a rigid material, whereby the outer shell 10 may disperse impact energy over a large area even though the impact may be effected on a small area of the helmet 1. The outer shell 10 may deflect, bend, buckle, or otherwise deform (panel-like deformations), when the outer shell 10 is impacted. Stated differently, when an extrinsic body hits the outer shell 10, the impact may be spread over an area larger than the impacted area of the inner liner 20 as a result of the panel-like deformations of the outer shell 10 to transmit the impact energy received on the outer shell 10 to a volume of the inner liner 20 surrounding the location of impact. That is typically the main role of the outer shell 10 in terms of impact energy transmission. In an embodiment, the outer shell 10 is made of thermoplastic material, such as polycarbonate, for instance. In other embodiments, the outer shell 10 may be made of composite materials, such as fiber-reinforced materials. A combination of composite and thermoplastic materials, and/or other rigid materials may be contemplated in some embodiments. The outer shell 10 is “rigid” in that the outer shell 10 may be resilient without (without or substantially without) deforming in compression (or “flatten” when compressed) to absorb energy, with no (or substantially limited) damping, as opposed to the deformations caused at the padding arrangement 30, and/or damping of the padding arrangement 30, for instance. Stated differently, the outer shell 10 has a substantially limited elastic deformation capability in contrast to the pads of the padding arrangement 30, and is substantially more rigid.

In some embodiments of the helmet 1, depending on the use it is intended for, there may not have such outer shell 10. For instance, the rigid outer shell 10 may be absent and replaced by one or more layers of fabric material or leather encapsulating or covering the inner liner 20 of the helmet 1. This is found typically in boxing headgears or helmets and rugby helmets (scrum caps), for instance. Also, in embodiments where the helmet 1 is a cycling helmet, for instance, the outer shell 10 takes the form of a thin layer of plastic sheet thermoformed and integral to the inner liner 20. In such case, the outer shell 10 has aesthetic functions rather than impact protection functions. As seen in some cycling helmet, for instance, such outer shell 10 may not form a continuous surface for covering the inner liner 20, as the inner liner 20 may be visually apparent from the outside of the helmet 1 and form portions of the outer surface of the helmet 1. In the case of cycling helmet, for instance, the outer shell 10 may not be considered as “rigid” and may not help in spreading the impact energy over a greater area of the inner liner 20.

In the illustrated embodiment, the inner liner 20 is connected to the outer shell 10 of the helmet 1. As mentioned above, the inner liner 20 includes a padding arrangement 30, which may be referred to as the energy-absorbing device of the helmet 1, as the primary function of the padding arrangement 30 is to absorb impact energy resulting from impacts received on the helmet 1, by an extrinsic body (e.g. ground or wall surfaces, projectiles or objects, a third party body part, etc.). Although the outer shell 10, by deforming and/or breaking may also absorb a certain amount of impact energy, in the context of the present disclosure, the outer shell 10 is excluded from the so-called energy-absorbing device of the helmet 1.

The inner liner 20 may be secured to the outer shell 10 in any suitable manner. In an embodiment, the inner liner 20 is secured to the outer shell 10 by adhesive bonding (e.g. glue, structural adhesive, etc.). Additionally or alternatively, the inner liner 20 may be co-molded with the outer shell 10, for instance. Additionally or alternatively, the inner liner 20 may be secured to the outer shell 10 using fasteners, such as rivets, screws, or other types of fasteners.

In addition to the padding arrangement 30, the inner liner 20 may include comfort paddings (not shown) that are typically soft and/or cushiony (i.e. substantially softer than the padding arrangement 30) and adapted to contact the wearer's head when the helmet is donned. The comfort paddings may typically deform upon donning the helmet 1 to conform to the wearer's head. Since the comfort paddings are deformable by mere pressure of the wearer's head when the helmet 1 is donned, the comfort paddings may solely absorb a negligible amount of impact energy, if any. The comfort paddings may include soft foam, liquid bladders and/or fabric materials, for instance. The comfort paddings may interface with the wearer's head when the helmet 1 is worn. The comfort paddings may be disposed within the inner cavity 11 of the helmet 1 at different locations to surround the wearer's head when worn, between the wearer's head and the padding arrangement 30. In an embodiment, the comfort paddings may be removably secured to the remainder of the inner liner 20, for instance to the padding arrangement 30, by Velcro™, and/or glue, or otherwise. The comfort paddings may be permanently or removably secured to the padding arrangement 30 and/or other components of the helmet 1 as permanent or replaceable parts of the inner liner 20, in other embodiments. In some cases, comfort paddings may be connected to the attachment device that secures the helmet 1 on the wearer's head. For instance, comfort paddings may be disposed on a head contacting side of straps of the attachment device to prevent the straps from contacting directly the wearer's head, throat or chin and/or for improving comfort of the wearer.

Referring to FIGS. 2 and 3, the padding arrangement 30 comprises a plurality of padding substructures 31, which are arranged together to form parts of the padding arrangement 30. The padding arrangement 30 is adapted to reduce linear and/or rotational acceleration of the wearer's head when receiving an impact, as discussed below.

As depicted in FIG. 4, an oblique impact made on the helmet 1 may be defined as an acceleration vector V originating from a surrounding environment of the helmet 1. The acceleration vector V extends toward the helmet 1. The acceleration vector V may be decomposed into a normal component a_(x) and a tangential component a_(y) with respect to an imaginary domed surface generally corresponding to the convex outer surface of the helmet 1, which may correspond to the outer shell 10 in embodiments where it is present. The normal component a_(x) of the acceleration vector intersects the helmet 1 normally to that domed surface. The normal component a_(x) of the acceleration vector V may thus be considered equivalent to the linear component of the oblique impact made on the helmet 1. Because of the tangential component a_(y) of the acceleration vector V, a “rotational” or tangential acceleration is induced to the outer shell 10 relative to the wearer's head. The tangential component a_(y) of the acceleration vector V may thus be considered equivalent to the “rotational” component of the oblique impact.

The helmet 1, and more particularly the padding arrangement 30 opposes to the normal and tangential accelerations by deforming. Such deformation results in energy absorption. In other words, the padding arrangement 30, by one or more padding substructures 31, individually or by reciprocal relationship, counteracts at least partially the normal and tangential accelerations of the acceleration vector defining the impact by deforming the one or more padding substructures 31 in a combination of compression and shear deformations (i.e. a deformation component oriented along a thickness T of the padding substructure 31 and a deformation component transverse to said thickness T of the padding substructures 31). This may at least partially decouple the acceleration induced to the outer shell 10 of the helmet 1 with respect to the wearer's head for an instant time upon impact.

The plurality of padding substructures 31 form parts of the padding arrangement 30 and are disposed at selected locations in the inner cavity 11 of the helmet 1, where the padding substructures 31 may deform in a combination of deformation in compression and shear in their own way. An aspect of the padding substructures 31 is that a ratio of impact energy absorbed in compression over impact energy absorbed by shear may be optimized, where such optimized ratio is dependent upon the impact force incidence. Depending on the embodiment, this optimized ratio may be minimized or maximized, depending on the impact force incidence. For instance, in an embodiment, the geometrical parameters of the padding substructures 31 are such that the shear deformation is maximized and provide absorption of, at least partially, the energy in shear induced by the oblique impact, while a greater proportion of energy may be absorbed by compression of the padding substructures 31 on the overall energy induced to the helmet 1 by the oblique impact. The geometrical parameters of the padding substructures 31 are such that a proportion of energy absorbed by shear deformation over the energy absorbed by compressive deformation is increased over a comparable structure without the geometrical parameters of the padding substructures 31. In a particular embodiment, such situation may be met when the oblique impact is at 450 with respect to a plane tangent to the outer surface of the helmet 1 at the impact location. This may be different in some embodiments, where, for instance, the geometrical parameters of the padding substructures 31 are such that the proportion of energy absorbed by shear deformation is greater than the energy absorbed by compressive deformation for a given oblique impact, for instance, a 45° oblique impact.

In an embodiment, the padding substructures 31 are connected together. This may be done in any suitable manner. For instance, the padding substructures 31 may be mounted on a layer of fabric that may stretch to allow the movement of outer shell portions, where the outer shell 10 is made of a plurality of shell portions that are movable relative to one another, as discussed above. At least one of the padding substructures 31 may be disconnected from other padding substructures 31, in some embodiments. Yet, in other embodiments, all the padding substructures 31 may be removably connected to one another, or not connected to any others. The padding substructures 31 may each be individually connected to the outer shell 10, although in some embodiments at least some of the padding substructures 31 may be indirectly connected to the outer shell 10 through other padding substructures 31 directly connected to the outer shell 10.

According to an embodiment, the padding substructures 31 may each be made based on their assigned location within the inner cavity 11 of the helmet 1. In other words, each padding substructure 31 may have a shape, size, composition and/or an internal macrostructure adapted to reduce the impact energy transmitted to the wearer's head, and absorb a least partially the impact energy by deforming, in response to an impact on one of the occipital portion, the frontal portion or the lateral portions of the helmet 1. In use, the occipital portion of the helmet 1 may receive an oblique rear impact defined by an acceleration vector V oriented in a back-to-front direction and obliquely relative to the helmet 1, with a tangential component a_(y) imparting a forward rotation of the helmet 1 (toward the front of the head) or a rearward rotation (toward the neck portion at the rear of the head) about the wearer's head, depending on the orientation of the tangential component a_(y). This is shown in FIG. 4 as an example. Thus, one or more padding substructures 31 disposed in the occipital portion of the helmet 1 has/have a set of features to counteract a rear impact and maximize its overall energy absorption by combination of deformation in compression of the padding substructure 31 against the normal component a_(x) of the acceleration vector V of the oblique rear impact, and deformation in shearing against the tangential component a_(y) of the acceleration vector of the oblique rear impact, along a direction generally aligned with such tangential component a_(y). This direction may be referred to as a preferential deformation direction. Stated differently, the padding substructures 31 are weaker against shear along the preferential deformation direction in a shear plane than against compression in a direction transverse (transverse or normal) to the preferential deformation direction, transverse to said shear plane in a direction generally aligned with the normal component a_(x). In other words, a shear rigidity of the padding substructures 31 along the preferential deformation direction is lower than a rigidity in compression of the padding substructures 31 along a direction transverse to the preferential deformation direction. Such rigidity may correspond to a compression modulus or a Young modulus, for instance. Additionally or alternatively, the padding substructures 31 may be weaker against shear along the preferential deformation direction than against shear in a direction transverse (transverse or normal) to the preferential deformation direction in said shear plane. In an embodiment, for a given impact load amplitude and incidence, a ratio of shear deformation along the preferential deformation direction over a compressive deformation oriented transversely from the preferential deformation direction is greater than 2. Stated differently, for a given imposed deformation amplitude and direction, a ratio of shear force along the preferential deformation direction over a force oriented normally from the preferential deformation direction, with such force being also a shear force or being a compressive force, is lower than 0.5. For instance, in some cases a ratio of shear deformation along the preferential direction over a deformation oriented transversely from the preferential direction, with such deformation being also a shear deformation or being a deformation in compression, is from 2 to 10, and more particularly in some cases from 4 to 6. In other embodiments, the ratio may be different. Stated differently, a shear resistance is lower than a compressive resistance, where the compressive direction extends transversely (transversely or normally) to the shear direction. Additionally or alternatively, the shear resistance along the preferential deformation direction may be smaller than a shear resistance in a direction transverse to said preferential deformation direction, where these shear directions extend transversely to the thickness T of the padding substructure 31.

The preferential deformation direction of the one or more padding substructures 31 located in the occipital portion of the helmet 1 correspond to the direction of the tangential component a_(y) of the acceleration vector V that causes the helmet 1 to rotate forwardly or rearwardly, as discussed above. In other words, the one or more padding substructures 31 located in the occipital portion are less resistant to shear along the preferential deformation direction than in a direction normal to said preferential deformation direction. In some embodiments, minimizing the ratio of constraint in shear over the constraint in compression for padding substructures 31 disposed in the helmet 1 at selected locations and receiving an oblique impact may help absorbing impact energy. This may be done by minimizing the energy transmitted in shear to the wearer's head, which typically causes rotational acceleration to the wearer's head, and/or maximizing the energy absorbed in compression deformation. This may decrease the rotational acceleration imparted to the wearer's head upon receiving an oblique impact. Some examples of padding substructures 31 that may achieve this are described later.

This similarly applies to the one or more padding substructures 31 located in the frontal portion of the helmet 1, and/or the one or more padding substructures 31 located in the lateral portions of the helmet 1, and/or the one or more padding substructures 31 located in the top portion of the helmet 1.

In an embodiment, the one or more padding substructures 31 located in a lateral portion of the helmet 1 may counteract a lateral impact received on the helmet 1, with the normal component a_(x) of its acceleration vector V causing compression of the padding substructures 31, and the tangential component a_(y) of its acceleration vector V causing shearing along the preferential deformation direction of the one or more padding substructures 31 located in the lateral portion of the helmet 1. The preferential deformation direction of the one or more padding substructures 31 located in a lateral portion of the helmet 1 extends in a left-to-right (or vice-versa) direction of the helmet 1, along the imaginary domed surface of the helmet 1 (rotation of the helmet 1 with respect to the wearer's head from one side of the wearer's head to the opposed side). The preferential deformation direction of the one or more padding substructures 31 located in a lateral portion of the helmet 1 may be oriented differently in other embodiments, such as in a rear-to-front (or vice-versa) direction of the helmet 1, for instance.

In an embodiment, the one or more padding substructures 31 located in the frontal portion of the helmet 1 may counteract a frontal impact received on the helmet 1, with the normal component a_(x) of its acceleration vector V causing compression of the padding substructures 31, and the tangential component a_(y) of its acceleration vector V causing shearing along the preferential deformation direction of the one or more padding substructures 31 located in the frontal portion of the helmet 1. The preferential deformation direction of the one or more padding substructures 31 located in the frontal portion of the helmet 1 extends in a rear-to-front (or vice-versa) direction of the helmet 1, along the imaginary domed surface of the helmet 1, similar to the preferential deformation direction of the one or more padding substructures 31 located in the occipital portion of the helmet 1. The preferential deformation direction of the one or more padding substructures 31 located in the front portion of the helmet 1 may be oriented differently in other embodiments, such as in a left-to-right (or vice-versa) direction of the helmet 1, for instance.

In an embodiment, the one or more padding substructures 31 located in the top portion of the helmet 1 may counteract a top impact received on the helmet 1, with the normal component a_(x) of its acceleration vector V causing compression of the padding substructures 31, and the tangential component a_(y) of its acceleration vector V causing shearing along the preferential deformation direction of the one or more padding substructures 31 located in the top portion of the helmet 1. The preferential deformation direction of the one or more padding substructures 31 located in the top portion of the helmet 1 extends in a left-to-right direction of the helmet 1, along the imaginary domed surface of the helmet 1 (rotation of the helmet 1 with respect to the wearer's head from one side of the wearer's head to the opposed side), similarly to the preferential deformation direction of the padding substructures 31 located in the lateral portions of the helmet 1. In other embodiments, the preferential deformation direction of the padding substructures 31 located in the top portion of the helmet 1 may extend in a front-to-back direction of the helmet 1, similar to the padding substructures 31 located in the frontal and occipital portion of the helmet 1.

The padding substructures 31 thus have respective sets of features for customizing their respective behaviour when experiencing a rear impact, a lateral impact, a frontal impact and/or a top impact, depending on their respective locations within the inner cavity 11 of the helmet 1. Some examples of sets of features that may contribute to this are described later.

In some embodiments, these preferential deformation directions may correspond to standardized load conditions or acceleration vector pertaining to standardized tests for linear and/or rotational impact protection of protective helmets. For instance, these standardized tests include:

-   -   the “Standard Test Methods for Equipment and Procedures Used in         Evaluating the Performance Characteristics of Protective         Headgear” (ASTM F1446), the contents of the 2019 Annual Book of         ASTM Standards with respect to this standard is incorporated         herein by reference;     -   the “Standard Specification for Protective Headgear Used in         Horse Sports and Horseback Riding” (ASTM F1163), the contents of         the 2019 Annual Book of ASTM Standards with respect to this         standard is incorporated herein by reference;     -   the “Standard Specification for Helmets Used in Recreational         Bicycling or Roller Skating” (ASTM F1447), the contents of the         2019 Annual Book of ASTM Standards with respect to this standard         is incorporated herein by reference;     -   the “Standard Specification for Helmets Used for Recreational         Snow Sports” (ASTM F2040), the contents of the 2019 Annual Book         of ASTM Standards with respect to this standard is incorporated         herein by reference;     -   the “Standard Performance Specification for Ice Hockey Helmets”         (ASTM F1045-16), the contents of the 2019 Annual Book of ASTM         Standards with respect to this standard is incorporated herein         by reference;     -   the Ski and Snowboard Helmets standard of the European Committee         for Standardization (CE EN1077), the contents of the standard         text is incorporated herein by reference;     -   CSA Z263.1 and CSA Z262.1, the contents of the standards texts         is incorporated herein by reference; and     -   Hockey and Football STAR, Drop 45.

Referring to FIGS. 5 to 9, an exemplary embodiment of the helmet 1 is shown with a padding arrangement 130 having padding substructures 131 with respective preferential deformation directions dependent upon the location of the padding substructures 131 within the inner cavity 11 of the helmet 1. As shown, the padding substructures 131 are disposed within the inner cavity 11 of the helmet 1 respectively at locations generally corresponding to the zones of the wearer's head with which they are configured to contact and/or face. In some embodiments, the sizes and shape of the padding substructures 131 are selected to mimic (mimic or reflect) the surface areas of the respective zones of the wearer's head with which they are configured to contact and/or face.

As shown, the padding arrangement 130 has a frontal substructure 131FZ located in the foremost portion of the helmet 1. The frontal substructure 131FZ may be configured to face and/or contact the frontal zone FZ of the wearer's head when the helmet 1 is worn and subject to a frontal impact. The padding substructure 131FZ is configured to cover at least part of (at least part of or a majority of) the forehead of the wearer. As shown, the frontal substructure 131FZ extends in a front-to-back direction of the helmet 1 from (adjacent to) a front peripheral edge 101 of the helmet 1, along a sagittal plane S-S of the helmet 1, towards the top of the helmet 1 (the pole of the helmet 1). The frontal substructure 131FZ extends laterally towards the opposite lateral sides of the helmet 1 between elevated lateral substructures 131ELZ at opposite sides of the inner cavity 11.

The elevated lateral substructures 131ELZ may be configured to face and/or contact the elevated lateral zones ELZ of the wearer's head when the helmet 1 is worn and subject to a lateral impact. The elevated lateral substructures 131ELZ are located in lateral portions of the helmet 1 within the inner cavity 11 to face sides of the wearer's head that are closer to the occipital portion of the helmet 1 than the frontal portion of the helmet 1. The elevated lateral substructures 131ELZ are located on opposite lateral sides of the helmet 1, on both sides of the frontal substructure 131FZ. There may have a gap 132 (empty space) between the frontal substructure lateral edges 133A and the forward facing edges 134A of the elevated lateral substructures in some embodiments. The frontal substructure lateral edges 133A and the forward facing edges 134A of the elevated lateral substructures 131ELZ may also be connected, by contacting each other for instance, whether or not bonded to each other, in some embodiments. While the elevated lateral substructures 131ELZ on the left and right side of the inner cavity 11 of the helmet 1 are shown as symmetrical with respect to a sagittal plane S-S of the helmet 1, they may be shaped and/or sized differently from each other in other embodiments. In the depicted embodiment, the elevated lateral substructures 131ELZ extend laterally rearwardly relative to the frontal substructure 131FZ of the helmet 1 along part of the front peripheral edge 101. The elevated lateral substructures 131ELZ extend from (adjacent to) the front peripheral edge 101 of the helmet 1, towards the top of the helmet 1 (the pole of the helmet 1). The elevated lateral substructures 131ELZ are disposed on opposite sides of the sagittal plane S-S of the helmet 1. The elevated lateral substructures 131ELZ extend between the frontal substructures 131FZ and posterior lateral substructures 131PLZ at opposite sides of the cavity 11.

The posterior lateral substructures 131PLZ are located rearward from the elevated lateral substructures 131ELZ within the inner cavity 11. The posterior lateral substructures 131PLZ may be configured to face and/or contact the posterior lateral zones ELZ of the wearer's head when the helmet 1 is worn and subject to a lateral impact. There may be a gap 132 (empty space) between forward facing edges 135B of the posterior lateral substructures 131PLZ and the rearward facing edges 134B of the elevated lateral substructures 131ELZ in some embodiments. The forward facing edges 135B of the posterior lateral substructures 131PLZ and the rearward facing edges 134B of the elevated lateral substructures 131ELZ may be connected, by contacting each other for instance, whether or not bonded to each other, in some embodiments. The posterior lateral substructures 131PLZ are disposed on opposite sides of the sagittal plane S-S of the helmet 1. While the posterior lateral substructures 131PLZ on the left and ride sides of the inner cavity 11 of the helmet 1 are shown as symmetrical with respect to the sagittal plane S-S of the helmet 1, they may be shaped and/or sized differently from each other in other embodiments. In the depicted embodiment, the posterior lateral substructures 131PLZ extend between the elevated lateral substructures 131ELZ and an occipital substructure 131OZ at the rear of the cavity 11.

The occipital substructure 131OZ is located rearward from the posterior lateral substructures 131PLZ within the inner cavity 11. The occipital substructure 131OZ has a head-facing surface that faces a head-facing surface of the frontal substructure 131FZ. The occipital substructure 131OZ may be configured to face and/or contact the occipital zone OZ of the wearer's head when the helmet 1 is worn and subject to a rear impact. There may be a gap 132 (empty space) between the forward facing edges 136A of the occipital substructure 131OZ and the rearward facing edges 135A of the posterior lateral substructures 131PLZ in some embodiments. The forward facing edges 136A of the occipital substructure 131OZ and the rearward facing edges 135A of the posterior lateral substructures 131PLZ may be connected, by contacting each other for instance, whether or not bonded to each other, in some embodiments. The occipital substructure 131OZ intersects with the sagittal plane S-S of the helmet 1, like the frontal substructure 131FZ.

The frontal substructure 131FZ, the elevated lateral substructures 131ELZ, the posterior lateral substructures 131PLZ and the occipital substructure 131OZ may surround circumferentially, in a crown-like disposition, the wearer's head and form energy absorbing structures dedicated to specific parts of the helmet 1 to protect specific zones of the wearer's head against impacts. A top substructure 131T may be located at the top (pole) of the helmet 1. The top substructure 131T may be configured to cover the highest portion of the wearer's head. As shown, the peripheral edges 137 of the top substructure 131T may be surrounded by interfacing edges 138 of the frontal substructure 131FZ, the elevated lateral substructures 131ELZ, the posterior lateral substructures 131PLZ and the occipital substructure 131OZ that coincide with the top substructure 131T.

While the various substructures 131 discussed above are illustrated each as a single part (one continuous part), one or more of the padding substructures 131 may be divided in a plurality of separate substructure segments (or sections), whether or not interconnected to one another. While shown as of similar or identical thicknesses, the substructures 131 may have different thicknesses, such that some substructures 131 may be thinner than other substructures 131 depending on the embodiments. The padding substructures 131 may also have one or more perforations extending across the padding substructures 131 to provide ventilation passages within the padding substructures 131 for comfort, as another possibility.

The padding substructures 131 discussed above are depicted with arrays of arrows oriented in different directions, which corresponds to preferential deformation directions particular to the dedicated location of the respective padding substructures 131 within the inner cavity 11.

The preferential deformation directions for the padding substructures 131 discussed above may correspond to that shown on the zones of the wearer's head illustrated on the skull SK of FIGS. 1A to 1E.

In the depicted embodiment, the preferential deformation direction of the frontal substructure 131FZ extends in the front-to-back direction, from the front peripheral edge 101, along the sagittal plane S-S of the helmet 1, toward a top of the helmet 1, which may correspond to toward the top substructure 131T. This corresponds to that shown in FIGS. 1A-1B, where the arrows extends from the orbit O towards the top of the skull SK. The preferential deformation direction extends along the curvature of the outer shell 10, and/or along a plane extending transversally to the thickness of the padding substructures 131.

In the depicted embodiment, the preferential deformation direction of the elevated lateral substructure 131ELZ extends upwardly, that is towards the top of the helmet 1. This corresponds to that shown in FIG. 1D, where the arrows extend from the ear (or external auditory canal AC) towards the sagittal suture SS2. The preferential deformation direction extends along the curvature of the outer shell 10, and/or along a plane extending transversally to the thickness of the elevated lateral substructure 131ELZ.

In the depicted embodiment, the preferential deformation direction of the posterior lateral substructure 131PLZ extends rearwardly with respect to the helmet 1, that is towards the occipital substructure 131OZ. This corresponds to that shown in FIG. 1D, where the arrows extends from the ear (or external auditory canal AC) towards the lambdoid suture SS2. The preferential deformation direction extends along the curvature of the outer shell 10, and/or along a plane extending transversally to the thickness of the posterior lateral substructure 131PLZ.

In the depicted embodiment, the preferential deformation directions of the elevated lateral substructure 131ELZ and the posterior lateral substructure 131PLZ are normal to each other.

In the depicted embodiment, the preferential deformation direction of the occipital substructure 131OZ extends in the back-to-front direction, from a rear peripheral edge 102 of the helmet 1, and along the sagittal plane S-S of the helmet 1, toward the top of the helmet 1, which may correspond to toward the substructure 131T if present. This corresponds to that shown in FIGS. 1B-1C, where the arrows extend from the occiput towards the coronal suture SS4 of the skull SK. The preferential deformation direction extends along the curvature of the outer shell 10, and/or along a plane extending transversally to the thickness of the padding substructures 131.

In the depicted embodiment, the preferential deformation directions of the posterior lateral substructure 131PLZ and the occipital substructure 131OZ are normal to each other.

In the depicted embodiment, the top substructure 131T does not have any preferential deformation direction like the other padding substructures 131. The top substructure 131T may have a preferential deformation direction in other embodiments. For instance, the top substructure 131T may have the same preferential deformation direction as one of the frontal substructure 131FZ, the elevated lateral substructures 131ELZ, the posterior lateral substructures 131PLZ and the occipital substructure 131OZ or a different/its own preferential deformation direction. As another possibility, segments (or sections) of the top substructure 131T may have a preferential deformation direction that corresponds to an adjacent padding substructure 131, such that the top substructure 131T may have a plurality of preferential deformation directions corresponding to the respective preferential deformation directions of the adjacent padding substructure 131.

While in the depicted embodiment the various substructures 131 all have their respective preferential deformation directions (except for the top substructure 131T in the depicted embodiment), the padding arrangement 30 may have only one or some selected ones of its padding substructures 131 having a preferential deformation direction in other embodiments of the helmet 1. As such, one helmet 1 may be configured to prioritize protection against one or some selected types of impact, i.e. to prioritize protection against impacts applied at one or more selected areas of the helmet 1 to counteract impacts applied in one or more specific directions on the helmet 1.

For instance, a helmet 1 may have an inner liner with a padding arrangement optimized for one specific type of impact (e.g. optimized only against frontal impacts, rear impacts or lateral impacts), such that a padding substructure covering only one specific zone of the wearer's head may have a preferential deformation direction while all other padding substructures of the padding arrangement may have no preferential deformation direction. For instance, in an embodiment, the frontal substructure 131FZ may have a preferential deformation direction such as discussed above while the other padding substructures 131 may not have any preferential deformation direction. As another possibility, the occipital substructure 131OZ may have a preferential deformation direction such as discussed above while the other padding substructures 131 may not have any preferential deformation direction. Yet as another possibility, selected ones of the padding substructures 131 may have their respective preferential deformation directions while other ones of the padding substructures 131 may not have a preferential deformation direction. For instance, in an embodiment, the frontal substructure 131FZ and the occipital substructure 131OZ may have their respective preferential deformation directions while the other padding substructures may not have any preferential deformation direction.

As discussed above earlier with respect to FIGS. 1F to 1N, just as zones on the wearer's head may be defined as transition zones TZ (also called overlapping zones) at junction areas between adjacent ones of the zones FZ, OZ, ELZ, PLZ, the padding arrangement 30 may have areas that mimic such transition zones TZ. This may limit drastic changes of damping behaviour and/or other padding properties, at transitions between adjacent padding substructures 131.

In the depicted embodiment, the padding substructures 131 do not have segments implementing such transition zones TZ discussed above, though this may be contemplated in other embodiments. As an example, hatched areas delimited by broken lines at the intersection of adjacent padding substructures are shown in FIGS. 5-9. FIGS. 10A to 10E show schematically different embodiments of transition zone segments 131TZ of the padding substructures 131, with exemplary preferential deformation direction configurations. The transition zone segments 131TZ shown in FIGS. 10A to 10E may be implemented in the hatched areas of FIGS. 5-9 with the patterns of preferential deformation directions shown. For instance:

-   -   as shown in FIG. 10A, the preferential deformation direction in         one or more of the transition zone segments 131TZ may be the         same as in one of the adjacent padding substructure 131;     -   as shown in FIG. 10B, one or more of the transition zone         segments 131TZ may have no preferential deformation direction;     -   as shown in FIG. 10C, one or more of the transition zone         segments 131TZ may have a preferential deformation direction         oriented in a mean direction of the preferential deformation         directions of each of the adjacent padding substructures 131         (e.g. if the adjacent preferential deformation directions are         normal to each other, then the mean direction would be oriented         at 450 from each one of the adjacent preferential deformation         directions);     -   as shown in FIG. 10D, one or more of the transition zone         segments 131TZ may have a preferential deformation direction         oriented in a weighted mean direction of the directions of each         of the adjacent padding substructures 131 (e.g. if A*x+B*y         represents vector components along axes x-x and y-y of a         resultant vector of the preferential deformation direction of         one of the adjacent padding substructures 131, and C*x+D*y         represents vector components along axes x-x and y-y of a         resultant vector of the preferential deformation direction of         another one of the adjacent padding substructures 131, where A,         B, C, D are the amplitudes of the shear resistance along axes         x-x and y-y of the respective padding substructures 131, then         the resulting vector of the preferential deformation direction         of the one or more transition zone         segment=(j*A+k*C)*x+(j*B+k*D)*y), with the weighting factors j         and k having values selected to reflect a desired relative         weight to be given to the adjacent preferential deformation         directions, e.g. more weight to be given to one of the adjacent         preferential directions than another; and     -   as shown in FIG. 10E, one or more of the transition zone         segments 131TZ may have a gradient of preferential deformation         directions from the preferential deformation direction of one of         the adjacent padding substructures 131 to the preferential         deformation direction of another one of the adjacent padding         substructures 131, such that one or more of the transition zone         segments 131TZ may have a plurality of preferential deformation         directions with an orientation that respectively progressively         changes from the preferential deformation direction of one of         the adjacent padding substructures 131 to the preferential         deformation direction of another one of the adjacent padding         substructures 131.

Other preferential deformation directions, including other distribution of preferential deformation directions within one or more padding substructures 131 may be contemplated in other embodiments.

Foam material typically used in helmets for making the inner liner 20 have isotropic properties, which may be less efficient and/or less suited for absorbing energy resulting from oblique accelerations/impacts affecting the foam material. Foam materials with isotropic properties may have relatively high shear rigidity when the foam material has a high compression rigidity, and thus isotropic foam materials may transmit a non-negligible amount of energy in a shear direction, perpendicular to a compression direction while impacted. In order to at least partially alleviate this, the energy-absorbing material(s) of the padding substructures 31 of the padding arrangement 30 are made of anisotropic materials, and/or have anisotropic properties because of their internal macrostructure(s) or configuration(s), for instance.

The padding substructures 31 may be made of one or more energy-absorbing materials. Energy-absorbing materials have viscoelastic properties, which may provide absorption of energy, as opposed to pure restitution or transmission of the impact energy over a short period of time. The damping properties of viscoelastic materials may provide more efficient absorption of impact energy over a short period of time (impact occurred over a very short period of time) than conventional elastic materials without viscoelastic properties. More particularly, in an embodiment, the padding substructures are made of elastomeric material, such as an elastomeric foam, a polymer foam, expanded polypropylene (EPP), etc. The materials used may also be auxetic materials, such as crystalline materials (e.g. zeolites), for instance.

In an embodiment, at least one of the padding substructures 31 is made of a composition of different energy-absorbing materials. For instance, in a particular case, at least one of the padding substructures 31 is made of a plurality of layers of different materials. There may be at least two different materials, if no more than two, each having different properties to absorb different types of impact. For instance, referring to FIGS. 11 to 22, at least a first layer 32 ₁ of material is made of a soft material (i.e. a material with low rigidity in compression) to absorb, at least partially, low intensity impacts. At least a second layer 32 ₂ of material may be made of a material stiffer than the at least first layer of material. This second layer of material, due to its greater rigidity, may absorb, at least partially, high intensity impacts. In an embodiment, the rigidity of the materials is measured as a Young modulus, for instance. In an embodiment, the rigidity of the second material is at least two times (e.g., 2×) the rigidity of the first material. This proportion may be different in other embodiments.

Additionally or alternatively, the layers of materials forming the one or more padding substructures 31 may have different thicknesses, an uneven thickness across one or more layers, and/or a non-linear shape (i.e. not flat, such as an oscillating shape). Examples of this are shown in FIGS. 11 and 12. Also, in other embodiments, the different materials of the padding substructures 31 may be distributed differently than by layers stacked one on the others, such as in a plot-like form as shown in FIG. 13A, or as a series of blocks 32 ₃ of different materials contained within one layer 32 ₁ of material, as shown in FIG. 13B.

In addition to or instead of padding substructures 31 having a composition of different energy-absorbing materials, one or more of the padding substructures 31 may have an internal macrostructure adapted to increase the shear deformation in a shear plane, along a preferential deformation direction, as discussed above. As such, a lower shear rigidity of the padding substructures 31 may be due to the internal macrostructure configured to weaken the padding substructures 31 against the shear load caused by the tangential component a_(y) of the oblique impact. The internal macrostructure may thus cause the padding substructures 31 to deform more than they would without such internal macrostructure. For instance, in an embodiment, the internal macrostructure may be created by material removal within the padding substructures 31. Referring to FIGS. 14-23, for instance, the internal macrostructure includes a plurality of channels 33 defined through the padding substructure 31. The number of channels 33 may vary, depending on the embodiments.

As shown, in an embodiment, the channels 33 may be elongated slits having a rectangular cross-section (shown with rounded edges). The slits extends longitudinally in a direction transverse to the thickness T of the padding substructure 31. When subjected to an oblique impact oriented transversely to the longitudinal dimension of the slits, the padding substructure 31 may shear (the slits may deflect). The slits are examples of features that may weaken the overall padding substructure 31 against shearing load in a preferential deformation direction, as discussed above.

In an embodiment, the rectangular cross-section of the slits has a height H that corresponds to 75%±5% of the thickness T of the padding substructure 31, and a width W of 1 mm±0.5 mm. A space S between adjacent slits measures 6.85 mm±0.5 mm. Other dimensions or proportions may be contemplated in other embodiments. Although the height H of the slits shown in FIG. 8 extends in a direction along the thickness T of the padding substructure 31, the slits may be obliquely oriented with respect to the thickness T of the padding substructure 31. This is shown in FIGS. 9 and 10, for instance. In an embodiment, referring back to FIG. 4, the slits are oriented such that their height H is transverse (in the case shown, normal or perpendicular) to the wearer's head when the padding substructures 31 are disposed within the inner cavity 11 of the helmet 1 at their assigned locations. Also, as shown, the slits may extend longitudinally along the imaginary domed surface of the helmet 1, along the convex surface of the wearer's head. In some embodiments, the slits extend longitudinally across the padding substructure 31, such that an opening is visible on opposed sides of the padding substructure 31. In other cases, the slits may not extend longitudinally all the way across the padding substructure 31.

In other embodiments, the channels 33 may have other cross-sectional shapes, such as an oval cross-section, diamond cross-section, although other channel 33 cross-sections may be contemplated. Examples of contemplated cross-sections of the channels 33 are illustrated in FIGS. 17 to 23. Additionally or alternatively, in some embodiments, the channels 33 may be filled with different materials instead of being hollowed.

Any suitable manufacturing techniques may be used to make the padding substructures 31. In an embodiment, the padding substructures 31 are made by additive manufacturing, such as 3D-printing manufacturing process, for instance. Such manufacturing technique may help making padding substructures 31 with complex shapes and/or combinations of different materials interconnected (e.g. interlaced, interlocked, merged, etc.) together to achieve a desired energy absorption pattern, such as padding substructures 31 with anisotropic properties, and padding substructures 31 having a complex internal macrostructure, such as a lattice macrostructure made of a network of bars or branches extending in a plurality of directions, for instance. Other types of manufacturing process may be used, such as injection-molding, with or without complementary or subsequent manufacturing processes (e.g. material removal process, such as grinding, drilling, etc.).

The embodiments described in this document provide non-limiting examples of possible implementations of the present technology. Upon review of the present disclosure, a person of ordinary skill in the art will recognize that changes may be made to the embodiments described herein without departing from the scope of the present technology. Yet further modifications could be implemented by a person of ordinary skill in the art in view of the present disclosure, which modifications would be within the scope of the present technology. 

1. A helmet for wearing on a wearer's head, the helmet comprising: an outer shell defining a convex outer surface and an opposite concave inner surface circumscribing an inner cavity to receive the wearer's head; an inner liner connected to the outer shell and located in the inner cavity, the inner liner contacting the wearer's head when the helmet is worn, the inner liner including a padding arrangement including: a plurality of padding substructures disposed at selected locations in the inner cavity, at least one of the padding substructures having a shear resistance along a first shear direction lower than a shear resistance along a second shearing direction, the second shear direction extending transversely to the first shear direction, and the first and second shear directions extending transversely to a thickness of the at least one of the padding substructures; and an attachment device for securing the helmet on the wearer's head.
 2. The helmet defined in claim 1, wherein the at least one of the padding substructures includes a plurality of separate substructure segments.
 3. The helmet defined in claim 2, wherein the separate substructure segments are interconnected to one another.
 4. The helmet defined in claim 1, wherein the at least one of the padding substructures includes a frontal substructure located in a foremost portion of the helmet within the inner cavity, the frontal substructure extending in a front-to-back direction of the helmet from adjacent to a front peripheral edge of the helmet towards a top of the helmet, the frontal substructure configured to face a frontal zone of the wearer's head such as to cover at least part of a forehead of the wearer's head.
 5. The helmet defined in claim 4, wherein the first shear direction of the frontal substructure extends in a front-to-back direction, from a front peripheral edge of the outer shell, along a sagittal plane of the helmet.
 6. The helmet defined in claim 1, wherein the at least one of the padding substructures includes an elevated lateral substructure located in a lateral portion of the helmet within the inner cavity to face a side of the wearer's head.
 7. The helmet defined in claim 6, wherein the first shear direction of the elevated lateral substructure extends upwardly towards a top of the helmet.
 8. The helmet defined in claim 1, wherein the at least one of the padding substructures includes a posterior lateral substructure located in a lateral portion of the helmet within the inner cavity to face a side of the wearer's head within the inner cavity that is closer to an occipital portion of the helmet than a frontal portion of the helmet.
 9. The helmet defined in claim 8, wherein the first shear direction of the posterior lateral substructure extends rearwardly with respect to the helmet, towards an occipital portion of the helmet.
 10. The helmet defined in claim 1, wherein the at least one of the padding substructures includes an occipital substructure located in an occipital portion of the helmet within the inner cavity, the occipital substructure is configured to face an occipital zone of the wearer's head.
 11. The helmet defined in claim 10, wherein the first shear direction of the occipital substructure extends in a back-to-front direction, from a rear peripheral edge of the helmet and along a sagittal plane of the helmet.
 12. A helmet for wearing on a wearer's head, the helmet comprising: an outer shell defining a convex outer surface and an opposite concave inner surface circumscribing an inner cavity to receive the wearer's head; an inner liner connected to the outer shell and located in the inner cavity, the inner liner contacting the wearer's head when the helmet is worn, the inner liner including a padding arrangement including: a plurality of padding substructures disposed at selected locations in the inner cavity, at least one of the padding substructures having a shear resistance along a shear direction lower than a compressive resistance along a compressive direction, the compressive direction extending transversally to the shear direction; and an attachment device for securing the helmet on the wearer's head.
 13. The helmet defined in claim 12, wherein the at least one of the padding substructures includes a plurality of separate substructure segments.
 14. The helmet defined in claim 13, wherein the separate substructure segments are interconnected to one another.
 15. The helmet defined in claim 12, wherein the at least one of the padding substructures includes a frontal substructure located in a foremost portion of the helmet within the inner cavity, the frontal substructure extends in a front-to-back direction of the helmet from adjacent to a front peripheral edge of the helmet towards a top of the helmet, the frontal substructure is configured to face a frontal zone of the wearer's head such as to cover at least part of a forehead of the wearer's head.
 16. The helmet defined in claim 15, wherein the shear direction extends in a front-to-back direction, from a front peripheral edge of the outer shell, along a sagittal plane of the helmet.
 17. The helmet defined in claim 12, wherein the at least one of the padding substructures includes an elevated lateral substructure located in a lateral portion of the helmet within the inner cavity to face a side of the wearer's head.
 18. The helmet defined in claim 17, wherein the shear direction extends upwardly towards a top of the helmet.
 19. The helmet defined in claim 12, wherein the at least one of the padding substructures includes a posterior lateral substructure located in a lateral portion of the helmet within the inner cavity to face a side of the wearer's head within the inner cavity that is closer to an occipital portion of the helmet than a frontal portion of the helmet.
 20. (canceled)
 21. The helmet defined in claim 12, wherein the at least one of the padding substructures includes an occipital substructure located in an occipital portion of the helmet within the inner cavity, the occipital substructure is configured to face an occipital zone of the wearer's head.
 22. (canceled) 